Questions are being asked about why so few fire engines were available initially.

It appears that some engines got stuck in the Kenyan capital's notorious traffic jams. Many engines at the scene also quickly ran out of water.

Soldiers and police even came with buckets to help put out the fire, Sylvia Amondi, who was at the airport to pick up a relative who had been due to arrive there, told AFP news agency.

"The international arrivals station has been completely destroyed, the roof has caved in and the floor is covered in debris and water," she said.

Jomo Kenyatta Airport

Busiest airport in east and central Africa, and seventh busiest in Africa

Handles six million passengers a year

Hub for neighbouring countries as well as cities as far away as Lagos, Johannesburg and Cairo - as well as gateway to continent for Europe and Asia

Serves 49 destinations in 23 countries, across five continents

Key export point for Kenya's flower industry, one of the country's top foreign exchange earners - Kenyan flowers account for 35% of flowers imported into the EU

A third of Europe's flower imports, and many fresh vegetables, come from Kenya and the Kenya Flower Council exporters' association described the fire as "disastrous".

Shares in Kenya Airways, which uses the airport as its main hub, fell 2% after the fire.

Foreign airlines which use the terminal include British Airways, Emirates, Qatar Airways, KLM, Turkish Airlines, South African Airways and Ethiopian Airlines. Several cancelled flights to Nairobi on Wednesday.

The country's anti-terrorism chief, Boniface Mwaniki, has said he does not believe the fire - which happened on the 15th anniversary of the bombings by al-Qaeda of the US embassies in Nairobi and Dar es Salaam, Tanzania - was connected to terrorism.